According to a report in Wednesday's issue of New Scientist magazine, transmission-related acute lung injury (TRALI), a preventable adverse immune reaction caused by antibodies in donated blood, is causing close to 500 deaths a year. Physicians usually see TRALI cases after a patient has received donated blood that has been exposed to several blood groups. Bloodsource, a California blood bank, estimates the disorder occurs in one in every 5000 transfusions and kills 500 people each year. The report's authors, who insist that TRALI is preventable, are calling for the implementation of enhanced screening procedures for donors who have been exposed to several blood groups.